Metal Gear Online uses much the same control scheme and equipment as Metal Gear Solid V: The Phantom Pain, but in a more competitive setting.
That really should tell you all you need to know, or at the very least tell you enough to sell you on the concept.
After all, the current PvP mode in MGS V is fairly enjoyable already, and it takes place on considerably smaller worlds than will be available in MGO.
Throw in the option to create a new custom character or, alternatively, to use the one you originally created in MGS V; custom classes that allow for a number of varying tactical approaches; a number of match types with differing objectives; and all of the shenanigans usually involved in a Metal Gear Solid adventure.
There’s a lot of room for Metal Gear Online to be a bucket load of fun, but it might also devolve into something fairly generic and “samey”.
It will all come down to mission types, their execution, the balance of classes and the continuous inflow of new, interesting content.
From MGO to MGS V
Crisis in Metal Gear Solid V – Don’t Fall Victim